Solved

Can't Ping Server and Tracert is routing wrong

Posted on 2011-09-28
4
1,918 Views
Last Modified: 2012-05-12
Hi Experts,

I am working on Server 2008 with three NIC's. There is one NIC dedicated to just connecting to an offsite backup server within our data center. However, the server can't ping (or connect) to the offsite backup server.

Here is what I have for my NIC info:

IP: 10.250.77.24
Subnet: 255.255.255.0
Gateway: Empty
DNS: Empty

When I run a ping 10.250.77.15 (backup server). Note; 38.65.32.17 is our ISP DNS server.

C:\Windows\system32>ping 10.250.77.15

Pinging 10.250.77.15 with 32 bytes of data:
Reply from 38.65.32.17: Destination host unreachable.
Request timed out.
Reply from 38.65.32.17: Destination host unreachable.
Reply from 38.65.32.17: Destination host unreachable.

Ping statistics for 10.250.77.15:
    Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),


I know the problem is the ping is routing out the wrong interface because here is my tracert results:

C:\Windows\system32>tracert 10.250.77.15

Tracing route to 10.250.77.15 over a maximum of 30 hops

  1    <1 ms    <1 ms    <1 ms  192.168.77.1
  2     1 ms     1 ms     1 ms  38.65.32.17
  3  38.65.32.17  reports: Destination host unreachable.

Trace complete.


Here is also my route table. NOTE: 192.168.77.64 is my NIC that is setup for internet access. I've removed my private NIC information as well.

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0     192.168.77.1    192.168.77.64    266
      10.250.77.0    255.255.255.0         On-link      10.250.77.24    266
     10.250.77.24  255.255.255.255         On-link      10.250.77.24    266
    10.250.77.255  255.255.255.255         On-link      10.250.77.24    266
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
     192.168.77.0    255.255.255.0         On-link     192.168.77.64    266
    192.168.77.64  255.255.255.255         On-link     192.168.77.64    266
   192.168.77.255  255.255.255.255         On-link     192.168.77.64    266
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link      10.250.77.24    266
        224.0.0.0        240.0.0.0         On-link     192.168.77.64    266
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link      10.250.77.24    266
  255.255.255.255  255.255.255.255         On-link     192.168.77.64    266
===========================================================================
Persistent Routes:
  Network Address          Netmask  Gateway Address  Metric
          0.0.0.0          0.0.0.0     192.168.77.1  Default

The odd part is I have three other servers with the same setup. I've checked the route tables and they are the same (just different local IP's) and those servers have no issues.

Any help is appreciated. Thanks!
0
Comment
Question by:RLComputing
  • 2
4 Comments
 
LVL 2

Expert Comment

by:Robert Silver
ID: 36717230
I think you need a gateway. Are you using DHCP orstatic IP ??
In either case you must have a default gateway to route to
0
 
LVL 1

Author Comment

by:RLComputing
ID: 36717553
It's setup with a Static IP . However it does works with no gateway on the other three servers with the same setup.
0
 
LVL 3

Accepted Solution

by:
rog2054 earned 500 total points
ID: 36718811
The backup server is on the same subnet as the 2nd NIC of the 'problem' server. As this is the same subnet no default gateway is necessary on that NIC.

As you point out RLComputing, the routing table looks correct.

A few questions/checks:
Can you ping from the backup server to this problem server?
Is there a firewall or other securty software running on the problem server?
Can you ping from the problem server to the 10.250.77.x address of any other server?

It could be that the backup server is sending ICMP Redirects, telling your server to go elsewhere (eg 192.168.77.1) to reach the destination. Although i'm not sure why this would be the case, especially as it is a local subnet. You could turn off the 'accept icmp redirects' option on the problem server, and then see if the problem persists. This is a registry change, so it depends on your internal change procedure etc as to how practical this is as a test.

Again, not sure how practical this would be to do as a test, but if you unplug (or disable within Windows) the 192.168.77.x NIC, can you then ping the backup server from the problem server?

Can you try swapping the switchport of this server and another 'working' server, and see if that makes a difference? (helps rule out if it is a network switch, or server config issue).

Are there any vlans, especially pvlans involved here? As that could be another culprit for upsetting things.

Hopefully i've given you a few ideas there. From the info provided there is no 'oh its that' fix i'm afraid, but this should get you started in the right direction (or rule those things out!)

0
 
LVL 1

Author Closing Comment

by:RLComputing
ID: 36719228
Thank you for getting my head in the right direction. The servers are all running on VMWare ESXi so we have vSwitches for each of the NIC's. On the problem server, all three NIC's where assigned to only one vSwitch. As soon as I reconfigured the server for each NIC to be assigned to the correct VMWare vSwitch everything began to work. Thanks!!
0

Featured Post

Maximize Your Threat Intelligence Reporting

Reporting is one of the most important and least talked about aspects of a world-class threat intelligence program. Here’s how to do it right.

Join & Write a Comment

Nslookup is a command line driven utility supplied as part of most Windows operating systems that can reveal information related to domain names and the Internet Protocol (IP) addresses associated with them. In simple terms, it is a tool that can …
Downtime reduced, data recovered by utilizing an Experts Exchange Business Account Challenge The United States Marine Corps employs more than 200,000 active-duty Marines with operations in four continents, all requiring complex networking system…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…

760 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

22 Experts available now in Live!

Get 1:1 Help Now